Brazilian fossil is most complete pterosaur ancestor – 08/16/2023 – Science

Who sees the earthy sediments in a ravine in the municipality of São João de Polêsine, in the interior of Rio Grande do Sul, does not imagine that there were discovered remains of an animal that can bring important information about the evolution of the lineage that originated, on the one hand , dinosaurs and, on the other, pterosaurs.

Brazilian paleontologists found the fossilized remains of the reptile Venetoraptor gassenae, a member of the Pterosaurmorpha lineage, which includes pterosaurs. The owner of the new fossil would be a “cousin” of the flying reptiles that lived from the end of the Triassic period, around 260 million years ago, to the end of the Cretaceous, 66 million years ago.

The finding sheds light on the group that includes the ancestor of pterosaurs and dinosaurs, with some unique features, such as the presence of an imposing beak and claws.

With an estimated age of 230 million years (Middle Triassic), the fossil is a lagerpetid, a group that includes small-sized reptiles, powerful claws for climbing and jumping skills. They are considered the closest non-flying relatives of pterosaurs.

However, the fossil record of this group was still limited to a few specimens. O Venetoraptor it is the second representative of the group with known cranial material.

The article describing the new species was the cover of this Wednesday’s edition (16) of the prestigious journal Nature. In addition to researchers from Brazil, the study includes scientists from Argentina and the United States.

According to paleontologist Rodrigo Müller, director of Cappa (Support Center for Paleontological Research of the Fourth Colony), linked to UFSM (Federal University of Santa Maria) and first author of the study, in addition to the new species, the discovery reveals that the lagerpetids exhibited a greater morphological diversity than previously imagined.

Both dinosaurs and pterosaurs evolved a variety of forms before becoming extinct. Lagerpetids, on the other hand, were limited to a few specimens, with much of their anatomy still unknown. The team led by Müller described in detail the partial skeleton of V. gassenaeincluding the presence of a hand with sharp claws.

“The idea that they were all jumpers and cursorials came from the description of the fossil Lagerpetonbut now we see a greater variety, with these claws specialized for something, we don’t know if it was for climbing trees, we believe so,” he said.

This morphology is more similar to the group’s reptiles found in locations where North America is today, and not to others found in South America. that there was this dispersion for the dinosaurs”, says the paleontologist.

In addition, an analysis of the fossil’s kinship with the rest of the group made it possible to quantify the times that each of the “morphotypes” (in general terms, the basic body pattern, also called bauplan) of lagerpetids, dinosaurs and pterosaurs appeared in the group. “There was this important evolutionary episode in the group with a disparity in forms long before dinosaurs and pterosaurs diversified,” explains Müller.

Region is a paleontological pole

The site of discovery is known as the Buriol site, in the municipality of São João de Polêsine, close to Santa Maria, a region where the oldest known dinosaurs in the world were found. The region is abundant in Triassic sediments that may yet reveal new forms of both the earliest dinosaurs and the flightless reptiles closest to pterosaurs.

The generic name of the new fossil refers to the tourist town of Vila Vêneto, in the municipality where the material was found, and raptor, due to its raptorial habit (grabbing prey). The specific name honors Professor Valserina Maria Bulegon Gassen, founder of Cappa/UFSM.

According to Müller, the region is a paleontological hub, which contributes to several discoveries, but also needs constant appreciation, both through the activity of researchers in the region and with the training of human resources. “The eyes of the whole world, when thinking about the origin of pterosaurs and pterosauromorphs, will have to turn to Brazil, for sure”, completes the paleontologist.

The new fossil will be displayed at the Cappa/UFSM exhibition, including the original material, to stimulate the interest of the public and young researchers in research in the region.